Saudi Arabia’s call for Gulf nations to combine into a single entity appears to lay the ground for some kind of union with Bahrain. King Abdullah first highlighted the security issues facing the region when its leaders met in December – nine months after the kingdom sent tanks to tame a pro-democracy movement in Bahrain. Speculation is now swirling about how the relationship between the strongest and weakest members of the six-nation bloc could evolve, ahead of a meeting of the Gulf Cooperation Council this week.

The old idea of a Gulf union has taken on a new meaning after the Arab uprisings. Saudi Arabia hasn’t given any details on what it envisions beyond the existing cooperation on security and selected financial issues. But the six Gulf countries won’t easily set aside their political differences just to please each other. And plans for a Gulf monetary union, loosely based on the European model, appear to be stuck following the intention of the UAE and Oman to opt out.

That leaves the focus on Bahrain and Saudi Arabia, which already share strong links. As well as underwriting security of the island state, the house of Saud already partially bankrolls its finances. Bahrain gets roughly 150,000 barrels per day of oil from the offshore Abu Safah field, operated by Saudi Aramco under a decades old agreement. The revenues generated from its share of the field accounted for as much as 70 percent of Bahrain’s budget revenues in 2010.

A full fiscal union would help Bahrain lower its borrowing costs. Even with current Saudi support, it may run a budget deficit at four percent of GDP this year. The IMF estimates Bahrain’s gross public debt is around 40 percent of GDP and total foreign debt is at almost 150 percent. Bahrain’s gross domestic product is barely five percent of that of the two kingdoms taken together.

But a union formalising the status quo carries risks that don’t make it worthwhile. A pre-emptive move would pour fuel on the flame of the protests. It would also antagonise Iran, which once laid claim to the majority Shi’ite island. Any transfer of Saudi social austerity would also kill Bahrain’s raison d’etre among the Saudi businessmen and expatriates who escape to Manama to relax. Saudi rhetoric paves the way for a stronger union in the event that Bahrain’s regime is overwhelmed – but in that case, union would be just a name for annexation. In the meantime, the move isn’t worth the bother.